Ringing migratory birds at Spurn Point - in pictures

BTO volunteers take a break at Spurn Point coastal reserve. The reserve has been managed by the Yorkshire Wildlife Trust since the 1950s after it was purchased from the Ministry of Defence. The 3.5-mile long, narrow and curving peninsula provides perfect opportunities for watching birds, marine and coastal wildlife Photograph: Dan Kitwood/Getty Images

The reserve, only 50 metres wide in some places, lies on the northern bank of the Humber Estuary and is significantly affected by coastal erosion. Due to Spurn's location, it is one of the UK's key areas for ornithological observation, as it is the first landfall for many migratory species on their way over the North Sea to Scandinavia and beyond Photograph: Dan Kitwood/Getty Images

Roe deer walk through the grassy dunes Photograph: Dan Kitwood/Getty Images

Knots fly over the estuary. The BTO says importance of ringing is to find out as much as possible about where a species breeds, its migration routes and life expectancy, as well as population trends Photograph: Dan Kitwood/Getty Images

Paul Collins of the BTO walks through a Heligoland trap. These large traps - a series of chambers that funnel the birds into a small enclosure - are named after the German archipelago in the North Sea where they were invented Photograph: Dan Kitwood/Getty Images

An MP3 device plays bird song to attract birds into a mist net Photograph: Dan Kitwood/Getty Images

A brambling is caught in a mist net. Many of the birds that migrate between Africa and Europe each year are declining in Britain and across Europe as a whole Photograph: Dan Kitwood/Getty Images

A great tit is held after being ringed by volunteers Photograph: Dan Kitwood/Getty Images

Volunteers Pete Smith (left) and Dave Smith capture a chaffinch and a greenfinch. The rapid intensification of agricultural systems and habitat loss in Europe has driven declines of some species and global climate change is implicated in the declines of others Photograph: Dan Kitwood/Getty Images

A volunteer holds a brambling before it is fitted with a ring. As migratory bird populations may be affected by threats on their breeding grounds, wintering grounds and stopover sites, they are particularly vulnerable to the effects of environmental change Photograph: Dan Kitwood/Getty Images

Volunteer Pete Smith sits in the ringing office Photograph: Dan Kitwood/Getty Images

A goldfinch is held after being ringed Photograph: Dan Kitwood/Getty Images

A greenfinch is weighed after being ringed by volunteers Photograph: Dan Kitwood/Getty Images

Bird sightings are marked down in a ringing office Photograph: Dan Kitwood/Getty Images

A greenfinch is held after being ringed Photograph: Dan Kitwood/Getty Images

Bird rings are assembled, ready for use. Placing a light, uniquely numbered ring around a bird’s leg is a reliable and harmless method of identifying birds as individuals Photograph: Dan Kitwood/Getty Images

A song thrush is ringed Photograph: Dan Kitwood/Getty Images

A volunteer holds a goldcrest after it has been fitted with a ring Photograph: Dan Kitwood/Getty Images

Volunteer Dave Williams releases a song thrush after being fitted with a ring Photograph: Dan Kitwood/Getty Images

A brambling is released by volunteers Photograph: Dan Kitwood/Getty Images